Inappropriately Sized Weapons: A creature can’t make optimum use of a weapon that isn’t properly sized for it. A cumulative –2 penalty applies on attack rolls for each size category of difference between the size of its intended wielder and the size of its actual wielder. If the creature isn’t proficient with the weapon, a –4 nonproficiency penalty also applies.
Does this mean that you can wield a large 2 handed weapon as medium 2 handed for a only -2 penalty but get a lot more damage? Isn’t that overpowered?